Double rate flow controller

ABSTRACT

A DOUBLE RATE FLOW CONTROLLER INCLUDING A MEANS FOR PERMITTING FLUID FLOW AT A FIRST HIGH FLOW RATE, A MEANS FOR REDUCING THE FIRST FLOW RATE TO A SECOND LOWER FLOW RATE AND A MEANS FOR REGULATING THE VOLUME OF WATER PASSING THROUGH THE FLOW CONTROLLER DURING THE HIGH FLOW CONDITION BEFORE THE HIGH FLOW RATE IS TERMINATED AND THE LOW FLOW RATE BEGINS.

Feb. 6, 1973 w. LIVINGSTON 3,714,964

DOUBLE RATE FLOW CONTROLLER Original Filed Oct. 24, 1968 INVENTORWILLIAM L. LIVINGSTON BY dimly A ORNEYS United States Patent 3,714,964DOUBLE RATE FLOW CONTROLLER William L. Livingston, Sharon, Mass,assignor to Factory Mutual Research Corporation, Norwood, Mass.

Original application Oct. 24, 1968, Ser. No. 770,248, now

Patent No. 3,592,270. Divided and this application Aug.

6, 1970, Ser. No. 61,801

Int. Cl. F16 13/04 US. Cl. 137-5133 4 Claims ABSTRACT OF TIE DISCLOSUREA double rate flow controller including a means for permitting fluidflow at a first high flow rate, a means for reducing the first flow rateto a second lower flow rate and a means for regulating the volume ofwater passing through the flow controller during the high flow conditionbefore the high flow rate is terminated and the low flow rate begins.

CROSS-REFERENCE TO RELATED APPLICATION This application is a division ofcopending application Ser. No. 770,248, filed Oct. 24, 1968, now Pat.No. 3,592,270.

BACKGROUND OF THE INVENTION The present invention relates to a fluidflow control device and more particularly to a fluid flow control devicefor use in a fire extinguishing system.

In a copending application entitled Method of Controlling Fire, Ser. No.766,475 filed Oct. 10, 1968, by the inventors William L. Livingston andRussell W. Pierce and assigned to the assignee of the present invention,and now Pat. No. 3,605,900, a fixed fire extinguishing system isdisclosed wherein fluid ablative material is formed by the addition of awater swellable polymer powder to water when the system is activated,which combines with the water and forms an ablative gel which isdispensed from sprinkler heads located over the fire. The gel materialis substantially more viscous than plain water and tends to cling to thesurfaces on which it is sprayed and therefore, its heat absorbingcapabilities are substantially greater than plain water. An automaticfire extinguishing system using this ablative material is thereforeeflective at lower flow rates and with a lower overall volume of waterthan with conventional plain water systems. However, when the fluidablative material is used in a conventional sprinkler system, healthcodes do not allow the ablative material to be maintained in thesprinkler system where the system is in fluid communication with thepotable water supply. Since this is generally the situation with themajority of sprinkler systems presently in use, the gel forming materialmust be added to the water supply after the sprinkler system has beenplaced in operation. In a conventional wet pipe fire sprinkler system,initially the flow through the sprinkler head nozzles is pure water. Thegelling powder which is subsequently added after the system commencesoperation, changes the pure water to the fluid ablative material. Infire extinguishing systems of this type it is desirable that the waterand gel material mixture be builtup to the maximum concentration levelas fast as possible to be the most effective. A feature equallyimportant, is to build up an accumulation of ablative material at thefire exposure location in the shortest possible time to maximize thefire extinguishing capabilities of the system.

To accomplish both of these ends, it is desirable that the systemprovide an initial high rate of flow from the sprinkler head nozzles.Subsequently, when the fluid ablative material is accumulated, thesprinkler flow may 3,714,964 Patented Feb. 6, 1973 ice SUMMARY OF THEINVENTION The present invention is directed to a double rate flowcontrol device adapted for use in a sprinkler type fire extinguishingsystem and which permits an initial high flow rate and a subsequentlower flow rate. This is accomplished by a flow regulating meansincluding a pressure operated dash pot to restrict the volume of fluidablative material passing through the sprinkler system after apredetermined volume has been passed through the flow control device.

Among the objects of the invention are the provision of a fluid flowcontrol device adapted for use with fire extinguishing systems usingfluid ablative material to initially maximize the build-up of theablative material at a fire location, and subsequently to maintain it ata sustaining level after the build-up of the material has beenmaximized, and the provision of a fluid flow control device forpermitting a first flow of fluid therethrough at a high flow rate and asubsequent second lower flow rate after a predetermined volume has beenpassed through the device at the first flow rate.

Other objects and further applicability of the present invention willbecome more apparent when taken from the detailed description givenbelow in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic diagram of a fireextinguishing system including a cross-section of the flow controldevice of the present invention shown in the high flow rate position;

EFIG. 2 is a cross-section of the flow control device of FIG. 1 shown inthe low flow rate position and FIG. 3 is a view of the system takenalong line 3--3 of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a fireextinguishing system of the fluid ablative material type includes awater supply source 2 which is coupled by means of a pipe line 4 to aplurality of sprinkler heads 6 (only one of which is shown in detail inthe drawing). A supply 8 of gelling powder material, upstream of thesprinkler heads 6, is connected to the system pipe line 4 by anauxiliary line 10. Each sprinkler head 6 is a conventional type andincludes a nozzle 12 and a water deflector 14 which is attached to thenozzle by means of a yoke 16. In the non-operative condition, the nozzle12 is closed by means of a cap 18 maintained in position by means of afusible link 20. The nozzle portion of the sprinkler head assembly isthreaded into the open end of the sprinkler head pipe line 4. The fireextinguishing system is preferably a wet pipe type, that is it containswater; although the invention is not restricted to such a system.

The dual rate flow control device of the present invention is generallydesignated by the reference numeral 30- in the drawings. It is normallypositioned upstream of the sprinkler head nozzle 12 in the sprinklerhead pipe line 4. The flow control device 30 is formed of a circularmounting base 32 made of a noncorrosive metallic plate, placed insealing engagement with the inside of the sprinkler head pipeline 4.This is accomplished such as, for example, by spot Welding prior to theassembly of the sprinkler system or by means of a threaded connection.The base 32 of the flow control device 30 includes a high flow orifice34 through which water is adapted to flow at a high rate when the systemis activated. The orifice 34 is formed by a tubular stand pipe 36, thelower end of which is attached integrally with the base 32. The upperportion of the stand pipe 36 extends vertically above the base 32 andincludes a circular flange 38 having an annular recess 40 to receive asoft rubber O-ring seal 42.

The upstream end of the flow control device 30 is provided with acircular plate 44, the outside perimeter of which generally correspondsto and is slidable within the interior of the sprinkler head pipeline 4.The plate 44 includes a plurality of small fluid flow apertures 46equally spaced apart in a radial direction in the plate 44, as shown inFIG. 3. One of the apertures 46a is positioned in the center of theplate 44 so as to be directly over the high flow orifice 34. Althoughfour apertures 46, in addition to the center aperture 46a, areillustrated, it will be appreciated that the number, size and locationof these apertures on the plate 44 may be altered depending upon theflow conditions desired.

The plate 44 is supported above the base 32 by means of an air-filleddashpot comprising a bellows 48, the lower end of which is secured tothe base plate 32 and the upper end of which is secured to the plate 44.The bellows 48, is filled with air when the system is in thenon-operative condition. The bellows 48 is vented to the atmosphere bymeans of a vent 50 which communicates with the bellows interior throughan opening 52 in the base 32. The rate of venting of the air from withinthe bellows 48 may be regulated in part by the size of the vent 50.

The operation of the flow controlled device will now be described. Inthe static or no flow condition of the fire extinguishing system, wateris present in the pipeline 4. As shown in FIG. 1, the plate 44 of theflow control device 30 is maintained in the upstream position by meansof the dashpot bellows 48. Since water is present in a static conditionon either side of the plate 44 there is no pressure differential actingupon the plate 44 and air is not vented within the bellows 48.

During a fire condition, temperatures of the surrounding area are raisedand the fusible link 20 melts to release the cap 18 and open the nozzle12. Water then begins to flow through the sprinkler 6 from the head pipeline 4 at a fairly rapid flow rate and is discharged onto the firelocation. Further upstream, the gelling powder material from the supply8 is mixed with the plain water from the supply 2 to form the fluidablative material. With the plate 44 in the upstream position, theinitial high flow rate is maintained since the fluid ablative materialflows through all of the small apertures 46 and on through the high floworifice 34. This permits the gelling material to be completely mixedwith the plain water in a minimum amount of time and maximizes the buildup of the fluid ablative material at the fire location. As the fluidablative material continues to flow in the pipeline 4 and through theflow control device 30, the line pressure gradually builds up upon theupstream side of the plate 44 forcing it downwardly against theresistance of the airfilled bellows 48. This causes the air to begradually vented from the interior of the bellows 48 through the vent50, which in turn allows the plate 44 to gradually move downwardlytoward the base plate 32 and the high flow orifice 34.

After a sutficient amount of air has been expelled from the bellows 48due to the pressure of the flowing fluid ablative material against theplate 44, the low flow position, as illustrated in FIG. 2, is reached.At this point the plate 44 is clamped against the flange 38 and theO-ring seal 42 of the stand pipe 36 by the fluid pressure in such a wayso that only the center aperture 46a on the plate 44 remains in flowcommunication with the high flow orifice 34. A seal is maintained atthis point by the line pressure and only the fire ablative materialflowing through the center aperture 46a is permitted to pass through thehigh flow orifice 34. It will be appreciated since the center aperture46a is smaller than the opening of the high flow orifice 34, the amountof fluid ablative material passing through the nozzle 12 and onto thefire location is substantially reduced.

Rate of flow is proportional to pressure and time and by determining theconstants of the system, the sprinkler system can be adapted to permit apredetermined volume of fluid ablative material through each sprinklerhead 6 at the high flow rate before the flow control device 30 acts toreduce the flow rate to the lower sustaining level. It will beappreciated that bellows will vent faster at higher pressures and assuch the flow control device 30 becomes a flow integrator to maintain asubstantially constant volume of high rate fluid flow.

Thus with the fluid flow control device of the present invention, aninitial high fluid flow rate is provided to allow the gel material tobuild up to a maximum at the fire location. For example, it has beenfound that the volume of fluid ablative material which accumulates afterapproximately 15 minutes at the high flow rate is sufficient undernormal sprinkler system pressures to insure the maximum fireextinguishing capabilities of the system. By calculating the ventingrate of the bellows 48, the size of the vent 50 may be established toinsure the desired duration of flows at the high fluid flow rate. Afterthe high rate fluid flow, the flow of fire ablative material iscontinued at a lower flow rate sufficient to sustain the fireextinguishing capabilities of the system and maintained at this rateuntil the fire is extinguished and the system shut off.

Generally, the fire extinguishing system is not used more than once,however, the fluid flow control device of the present invention may bereused by reinflating the dashpot-bellows to reset the upper plate toits static flow position.

It will be appreciated that the above description of the double-rateflow control device is illustrative only and numerous modifications andvariations may be made in light of the above teachings. It is thereforeto be understood that within the scope of the appended claims, theinvention may be practiced otherwise than as specifically describedherein.

I claim:

1. A fluid flow controller comprising a housing having an inlet forconnection to a source of fluid and an outlet for discharging saidfluid; and means defining a first and second fluid passage in saidhousing to respectively pass fluid at a first and second flow ratebetween said inlet and outlet, said means including a dashpot assemblyhaving a base defining a high-flow orifice and a plate defining aplurality of low-flow orifices for fluid in said housing, said platebeing movable with respect to said base in response to a predeterminedfluid pressure in said housing and being adapted to attain a firstoperational mode in which said high-flow orifice is in fluidcommunication with a plurality of said low-flow orifices to establishsaid first fluid passage, and a second operational mode in which saidhigh-flow orifice is in fluid communication with one of said low-floworifices to establish said second fluid passage, said dashpot assemblydefining a chamber adapted to be filled with air, said chamber in itsfilled condition maintaining said plate in said first operational modewhereby said plurality of low-flow orifices are spaced from and in flowcommunication with said high-flow orifice, said chamber in its emptycondition maintaining said plate in said second operational mode wherebyall but one of said plurality of low-flow orifices are positioned out offluid communication with said high-flow orifice.

2. The controller of claim 1 wherein said chamber is defined by abellows attached between said base and said plate and adapted to befilled with air, said bellows being filled with air in said firstoperational mode of said dashpot assembly, said bellows being emptied ofair in said second operational mode of said dashpot assembly.

3. The controller of claim 2 wherein said dashpot assembly furtherincludes means for venting said chamber in response to a predeterminedmovement of said plate with respect to said base.

4. A device for regulating fluid flow through a conduit comprisingmovable means for creating a restriction in said conduit, said movablemeans being movable in said conduit from a first position to a secondposition in response to fluid flow through said conduit, and meanscooperating with said movable means to maintain a substantially constantrate of fluid flow through said conduit during said movement and tochange the fluid flow rate through said conduit in response to saidmovable means attaining said second position, said movable means beingadapted to stay in said second position despite a later reduction ofsaid fluid flow rate.

6 References Cited UNITED STATES PATENTS 3,160,212 12/1964 Reid 169-201,418,096 5/1922 Royer 137-517 2,318,962 5/1943 Parker 137514.52,365,994 12/1944 Ashton 138-31 2,688,984 9/ 1954 Snyder 138-313,282,323 11/1966 Katz et al 138-45 X 2,845,087 7/1958 Thomas 137-5043,308,798 3/ 1967 Snider 137-504 X FOREIGN PATENTS 670,293 4/ 1952 GreatBritain 137-504 ALAN COHAN, Primary Examiner D. J. ZOBKIW, AssistantExaminer US. Cl. X.R.

